Community-antenna television (CATV), often referred to simply as cable TV, uses coaxial cable to distribute standard television signals to customers receiving the service. Generally, CATV systems are accessed by greater numbers of users than access either local area network (LAN) or metropolitan area network (MAN) systems. CATV systems typically include a head end at which signals that are received from the source of programming material are processed for transmission over the system, a trunk system, which is the main artery carrying the processed signals, a distribution system, which is a bridge from the trunk system lines and carries signals to subscriber areas, and subscriber drops, which are fed from taps on the distribution system to feed subscriber TV receivers.
In order to service the large number of subscribers positioned randomly over the very large geographic area covered by a CATV system, the head end has both wireless and wired connections to distribution systems or remote head ends, which connect to yet further distribution systems. These distribution schemes include the use of satellites.
The primary goal of CATV has been to provide high quality TV signals for subscribers. However, today some CATV systems use optical fiber cable to increase the number of channels that can be carried. These systems also have some interactive communications between the subscribers and the programming source, and between subscribers. As a result, CATV systems can carry many more TV channels than ever before, as well as provide other types of communications services on a limited basis.
CATV systems have a spanning tree topology. In principle, this could be adapted to expand the interactive communications capability that now exists in CATV systems. One such interactive communications capability is that provided by a packet-switched network connection to subscribers via a modem at the subscriber's location, also known as a cable modem. In response to packet-switched information being carried on CATV systems, the CATV network topology typically requires an increased number of spanning tree networks to provide greater data bandwidth to subscribers by reducing the total number of subscribers on any one network. Typical systems may only be able to accommodate between 200-300 subscribers per spanning tree network. Therefore, a total service area which includes, for example, 10,000 subscribers, may require up to 50 network ports at the head end.
The increased number of network connections at the head end aggravates at least two problems. First, head end coaxial cables are typically held in place with threaded connectors, and it is difficult to connect and disconnect the cables with a wrench if they are in close physical proximity to each other. The greater the number and density of the connections, the greater the difficulty is in connecting and disconnecting them.
Second, to allow for expandability of the network and ease of repair, the head end typically has multiple electronic modules to which the network connections are attached. The electronic modules are usually stacked vertically on top of one another in a rack. If an electronic component in a module fails, the module may be removed from the system without affecting the connections of the other modules. However, because the network connections are attached directly to a module, they must all be disconnected from the faulty module and reconnected to a new module before service to subscribers can resume. The necessity of disconnecting and reconnecting the network connections greatly increases the mean time to repair (MTTR).
Therefore, there is a need for a way to easily connect network connections to a head end which allows for system expandability and quick repair.